Single chip modules are electronic packages that contain a single microelectronic device that is coupled to an interconnect substrate. Multiple chip modules (MCMs) are electronic packages that may contain any number of discrete microelectronic devices having similar electrical characteristics and/or similar electrical paths that are coupled to a single MCM interconnect substrate. MCMs comprise at least two discrete devices encapsulated therein, for example a processor unit or a memory unit and related logic units. Additional discrete microelectronic devices that may be contained within an MCM are resistors, capacitors, inductors, and the like. The basic concept of the MCM is the interconnections between the microelectronic devices and the ability to decrease the average spacing between them and form a single package. These interconnections include connecting the input/output (I/O) conductors on the devices to the interconnect substrate, which may comprise numerous different layers to provide the interconnections between the different mounted discrete components and the interconnections needed to interface the MCM to an external application board (i.e. printed circuit board (PCB)).
Conventional single and multi chip modules function at a component level, meaning a number of discrete modules are mounted to the application board that serves as an interconnecting structure. Shielding from radiation, and more specifically from radio frequency interference (RFI) and electromagnetic interference (EMI), is required to prevent performance degradation of the individual devices within each of the modules. Many times this shielding is required due to the final application and is application specific (i.e. partial RFI/EMI shielding with cleaning capabilities or complete RFI/EMI shielding). Shielding of RFI and EMI emitted from and absorbed by the components within the module and from adjacent modules is typically achieved by placing a metal lid over the individual device or devices that serve as part of the discrete module. The metal lid is formed as a simple cavity-type structure having a planar surface and substantially perpendicular sidewalls extending therefrom about a perimeter. The lid is positioned to cover or encapsulate the devices, such that the perpendicular sidewalls rest on the surface of the interconnect substrate to which the devices are mounted. The lid may be soldered to the interconnect substrate about its perimeter. The lid is typically formed of a material that provides shielding of RFI and EMI, yet unwanted propagation of RFI and EMI has been detected at points below where the lid and interconnect substrate are coupled (i.e. through the substrate edges and through the thickness of the substrate and around the perimeter of the I/O region).
As a result of the foregoing shortcomings, conventional chip modules, including single and multi chip modules, are limited in terms of use where RFI and EMI propagation may cause a problem. Accordingly, it is desirable to provide an RFI and EMI shielded module and method of shielding of the microelectronic device or devices within a module from RFI and EMI that propagate through the interconnecting substrate. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.